Ventilating system for compartmented buildings

ABSTRACT

A high efficiency ventilation system for a compartmented building wherein heat from exhaust air removed from a region in the building is transferred, by means of an air-to-air heat exchanger, to fresh supply air being provided to the region, to regulate the delivery temperature of the latter.

United States Patent Darin 1 Apr. 18, 197 2 VENTILATING SYSTEM FOR R rnces Cited COMPARTMENTED BUILDINGS UNITED STATES PATENTS [72] Inventor:William J. Darin, 2201 N. Kellingsworth, 2,488,333 11/1949 Schlachter..l65/66 X Portland, Oreg. 97211 P E J h J C b rzmary xammero n am y[22] 1970 Attorney-Kolisch & Hartwell .N 31,137 [21] Appl 57 ABSTRACT[52] U s 165/66 A high efficiency ventilation system for a compartmented[51 1 3/02 building wherein heat from exhaust air removed from a region58] d "165/16 66 in the building is transferred, by means of anair-to-air heat le exchanger, to fresh supply air being provided to theregion, to

regulate the delivery temperature of the latter.

W H 9 Claims, 2 Drawing Figures 'l w I HEAT EXCHANGER ii llPATENTEIJIPII I8 I972 I 7 3,656,542

'Il' HEAT EXCHANGER I "I I 'I 8h I I HEAT 1% l HEAT I I LEXCHANGER I[-1- "EXCHANGER] I I ('79 7& 60 755 I m xaa' Q 1 I) I I J I 79 73 14 I78 2 I 2 78' I I I I I L l 64" I F IG. 2

I I 63-\RE;%RN F::

G 69 E HUIIAIDIFIER l" i HEATING I 70 AND 67 I COOLING com I I WILLIAMJ. DARM GI INVENTOR.

| BY KM+ 14M,

' ATTY.

VENTILATING SYSTEM FOR COMPARTMENTED BUILDINGS BACKGROUND OF THEINVENTION The present invention concerns an improved ventilation systemfor compartmented buildings. More particularly, the invention concerns aventilation system wherein heat from the spent air of a compartment ofthe building is utilized to regulate the final delivery temperature offresh air supplied to the compartment without mixing the spent air andfresh air.

In heating and ventilation of compartmented buildings, such asmultistory office buildings, it is conventional to provide separatesystems for the various compartmented areas of the buildings. Thus, theheating and ventilation requirements are quite different for theinterior or core space of such buildings as opposed to the spaceadjacent the exterior walls, for example.

To be more specific, the usual air ventilation system for the exteriorspace of multistory buildings includes both hot and cold supplies toeach floor. However, since the core space of the building rarelyrequires heating, it is usual to provide only a supply of cool air,having a temperature near 60 Fahrenheit for example, to each floor forthe interior space. Separate regulating means are provided at each floorto add heat to the latter supply and control the final temperature ofthe air delivered to the interior space.

Furthermore, largely due to the effects of body heat of the occupantsand heat generated by lighting systems, the exhaust air from both thecore space and exterior space of multistory buildings is of relativelyhigh temperature, whether the building is being heated or cooled. Forexample, it is not unusual for the exhaust air from the compartments ofa multistory building to reach temperatures in the range of 90-l30Fahrenheit.

Consequently, systems have recently been designed for utilizing heatfrom the spent air of building compartments to regulate the finaltemperature of the supply air to the compartments. This is generallydone by mixing the spent exhaust air and the fresh supply air together,by means of various regulating equipment, to achieve the desireddelivery temperature of supply air. It should be apparent that onereason for utilizing such systems is to recover heat that is normallylost with the exhaust air and to thereby increase the efficiency of theventilation system. Another reason for the use of such systems is toprovide an effective control for the final delivery temperature of thefresh air.

Building construction codes presently in force in most areas permitmixing of limited amounts of exhaust air to fresh supply air; and insome cases the added proportion of exhaust air may reach 25 percent ofthe supply volume. However, it should be clear that there are manyreasons why such practice is not ideal. Specifically, the incorporatedexhaust air is stale and contains significant amounts of pollutantmaterials such as smoke, carbon compounds and gas, for example.Furthermore, due to the limited space between floors in conventionalbuildings and other economic considerations, it is not feasible toprovide separate filter means and humidity control equipment on eachfloor. Consequently, ventilation systems known in the prior artutilizing incorporated exhaust air are not capable of maintaining theideal humidity control and air freshness possible with directventilation systems.

SUMMARY OF THE INVENTION Accordingly, it is an object of the inventionto provide an improved ventilation system having unique temperaturecontrol means for compartmented buildings.

It is another object of the invention to provide a high efficiencyventilation system which utilizes heat from the air exhausted from aspace of the building to regulate the final temperature of the fresh airdelivered tothe space.

It is a further object of the invention to provide a high efficiencyventilation system for compartmented buildings which provides fresh,humidity controlled supply air of closely regulated temperature to allcompartments of the building.

These and other objects of the invention are attained by a ventilationsystem which features separate supply and exhaust systems for thebuilding compartments. The warm air exhausted from a compartment of abuilding and the cool, fresh air supplied to the compartment arecounterflowed through an air-to-air heat exchanger. Transfer of heatbetween the fresh and exhaust air is achieved and the supplies arecompletely isolated from each other. Regulating means are provided toselectively control the amount of warm exhaust air flowing through theheat exchanger to closely control the delivery temperature of the supplyair to the other compartment. Since the supply air is delivered througha completely closed system of ducts, effective filtering and humiditycontrol is possible by means of a conventional central control locatedon the building roof or in the basement.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects and advantages of thepresent invention will become apparent from the following detaileddescription of the invention when taken in conjunction with theaccompanying drawings, wherein:

FIG. 1 is a right elevation view in partial section of the utility areabetween the ceiling and floor of a multistory building, showing featuresof the ventilation system of the invention; and

FIG. 2 is a partial schematic diagram illustrating a ventilation systemdesigned in accordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 1, a utilityspace 10 is generally indicated, of the type usually found in a multiplelevel building, between a ceiling 14 of an office on one level and afloor 12 of the next highest level of the building. As indicated by theflow arrows, ventilating air of controlled temperature is supplied inconventional fashion to the lower level office, through a diffuser 11 inthe ceiling and exhausted through ceiling vents 15 to space 10.

Various ventilation equipment is located within space 10 supported inthe conventional fashion from the bottom surface of floor 12 by suitablemembers 13. More specifically, an air-to-air heatexchanger 18 isprovided adapted to promote heat exchange between two separatecounterflowing supplies of air of different temperatures. The exchangeris of conventional design and might comprise an exchanger of the typedescribed in U. S. Pat. No. 3,381,747 to William J. Darm.

Exchanger 18 includes a first inlet duct 19 communicating with space 10and a first outlet duct 20 connected to a return air duct 16.-Retum airduct 16 is connected to a main return duct, not shown, through which thereturn air is eventually forced by a return fan to the open atmosphere.Return duct 16 also includes a vent opening or passage means 22 formedtherein on the downstream side of the exchanger the size of the openingis adjusted through making adjustments in adjustable means or door 23such door being moved under the force of a thermostatically controlledmotor 24. What is referred to as a heat dissipating course in theexchanger connects inlet duct 19 to outlet duct 20.

Exchanger 18 further includes a second inlet duct 26 adapted to receivefresh supply air from supply duct 27 which provides fresh supply air ofa predetermined temperature from a source, not shown. The exchanger alsoincludes a second outlet duct 28 which is connected to a supply duct 29for furnishing ventilation air of regulated temperature to the diffuser11. What is referred to as a heat receiving course in the exchangerconnects inlet duct 26 and outlet duct 28.

For purposes of explaining the operation of the elements of FIG. 1, itmay be assumed that the space 10 comprises an office space of thebuilding adapted to receive ventilating air from a first supply at adesired room temperature. In that event, it might be expected that theexhaust air vented to space 10 will be of a temperature in the range of-l30 Fahrenheit. It may also be assumed that supply duct 29 contains airof a temperature below room temperature, for example near 60 Fahrenheit,from a main supply source.

To regulate the delivery temperature of the supply air, the latter isforced through the heat exchanger while spent air from space iscounterllowed through the exchanger. Consequently, heat from the spentair is transferred to the supply air until the latter reaches a suitabledelivery temperature. Precise temperature regulation is attained bycontrolling the volume of exhaust air flowing through the heatexchanger, by means of the thermostatically controlled motor 24. Thus,when the motor controlled door 23 is closed all the air exhausted fromspace 10 is forced through the exchanger. However, when the door isopened, a draft is created downstream of the exchanger and the volume ofexhaust air forced through the exchanger is significantly reduced. Thisresults in a lower heat exchange rate within the exchanger and a lowerdelivery temperature of the supply air. The motor controlled door, thevent or vent opening 22 and the inlet duct 19 function as aproportioning means in the construction.

It should be apparent that the apparatus described permits theutilization of heat from exhaust air which would otherwise be wasted andthereby significantly increases the efficiency of the buildingventilation system. Furthermore, the increase in efficiency is derivedwithout contaminating the supply air or interfering with filtering andhumidity control of the supply air by means of equipment located in acentral station elsewhere in the building. Finally, the inventionprovides an independent temperature control means for each compartmentof the building.

Referring now to FIG. 2, a system is shown including equipment similarto that of FIG. 1 for ventilation of one or more compartments 52, 54 inaccordance with the invention by utilizing heat derived from the exhaustair of the compartments. While multiple compartments have been shown,the system of the invention may be used with one compartment.

As shown, a central ventilation station 60 is provided of the typeusually installed in the basement or upon the roof of a compartmentedbuilding. Station 60 is adapted to condition and furnish fresh supplyair under the force of supply fan 61 through a main supply duct 62, andis adapted to receive and vent polluted exhaust air under the draft ofreturn fan 63 from a main return duct 64. The exhaust air is dischargedto the atmosphere through a discharge duct 65 and makeup air is suppliedto the system via a makeup duct 67 which communicates with theatmosphere, all in conventional manner. In addition, the usualhumidifiers 69 and heating and cooling coils 70 are provided tocondition the air supplied to duct 62.

Identical ventilation units 73, 74 are provided for compartments 52, 54,respectively. Each of the units is constructed and arranged like theequipment of FIG. 1. Only unit 73 will be described, it being understoodthat unit 74 is similar in construction and operation.

Unit 73 includes an air-to-air heat exchanger 76 secured within theutility space above compartment 52. The exchanger is adapted to receivefresh supply air of about 60 Fahrenheit from main duct 62, and isarranged to deliver conditioned supply air of a desired roomtemperature, for example near 70 Fahrenheit to compartment 52 via duct78. Exchanger 76 further includes an exhaust air network comprisinginlet 79 adapted to receive exhaust air from compartment 52, as well asan exhaust outlet 80 adapted to deliver the exhaust air to return duct82. The return duct includes a vent opening 83 downstream of theexchanger adapted to be selectively opened or closed by means of door 85controlled by motor 86. The exhaust air is finally delivered from returnduct 82 to the main return duct 64. In a manner similar to the operationof the elements of FIG. 1, the exhaust air is flowed through theexchanger in a direction opposite the flow of supply air therethrough.Heat derived from the exhaust air is transferred to the supply air beingconditioned by the exchanger to a final delivery temperature forcompartment 52.

The system described includes filtering and humidity control of thesupply air and utilizes heat from the exhaust air without incorporatingpollutants therefrom. While two building compartments have been shownsupplied in parallel with supply air from duct 62 and serviced by returnair duct 64, it

should be understood that any additional number of units desired couldbe incorporated in a similar system.

It is claimed:

1. A ventilating system for a building with means for regulatingtemperature in selected regions of the building including,

an air-to-air heat exchanger for each of said selected regions, eachexchanger having a heat receiving course and a heat dissipating course;

a fresh air supply duct;

an air return duct;

a connection between the fresh air supply duct and the heat receivingcourse of each exchanger;

a connection between the return duct and the heat dissipating course ofeach exchanger;

an air diffuser connected to the heat receiving course of each exchangerfor directing air from the receiving course into a selected region ofthe building; and

proportioning means for channeling spent air from a selected region ofthe building into said return duct with part of said spent air travelingthrough the said heat dissipating course and part of said spent airbypassing said heat dissipating course.

2. A ventilating system as described in claim 1, wherein saidproportioning means includes a vent formed in said return duct, covermeans for selectively closing said vent, and temperature responsivemeans for controlling said cover means.

3. A ventilating system as described in claim 2 further including meansfor supplying fresh air to said supply duct at a temperature below thedesired room temperature.

4. A ventilating system as described in claim 3, further including meansfor collecting spent air in an elevated portion of said spaces at anelevated temperature.

5. A ventilating system as described in claim 4, further including acentral conditioning station connected to said air supply duct and saidair return duct for filtering and conditioning said fresh air.

6. Ventilation apparatus for a building having a compartment comprising,

an air-to-air heat exchanger having a pair of heat exchanging coursesextending therethrough,

a fresh air supply duct and means connecting said supply duct to one endof one of said courses,

an air diffuser connected to the opposite end of said one course fordirecting air from said one course into said compartment,

an air return duct through which spent air is exhausted from thecompartment and means connecting said air return duct to one end of theother of said pair of courses,

first passage means accommodating air flow from said compartment intothe opposite end of said other course thus to introduce air into saidair return duct,

second passage means accommodating air flow from said compartment intosaid air return duct with such bypassing the said other course of theexchanger thus to introduce air into said return duct, and

adjustable means operable on adjustment thereof to change in the airintroduced into said air return duct the proportion of such air which isintroduced by said first passage means and the proportion of such airwhich is introduced by said second passage means.

7. The apparatus of claim 6 wherein said compartment is bounded by aceiling and a utility space in the building is provided above saidceiling, the exchanger is located above said ceiling in said utilityspace, and said first and second passage means communicate with saidcompartment through said ceiling.

8. The apparatus of claim 6, wherein said adjustable means isthermostatically controlled.

9. Ventilating apparatus for a building with means for regulating thetemperature of air in selected regions of the building comprising,

the receiving course into a selected region of the building,

an air return duct, and proportioning means for each exchanger forchanneling spent air from a selected region of the building into saidair return duct with part of said air traveling through said heatdissipating course of the exchanger and part of said spent air bypassingsaid heat dissipating course.

1. A ventilating system for a building with means for regulatingtemperature in selected regions of the building including, an air-to-airheat exchanger for each of said selected regions, each exchanger havinga heat receiving course and a heat dissipating course; a fresh airsupply duct; an air return duct; a connection between the fresh airsupply duct and the heat receiving course of each exchanger; aconnection between the return duct and the heat dissipating course ofeach exchanger; an air diffuser connected to the heat receiving courseof each exchanger for directing air from the receiving course into aselected region of the building; and proportioning means for channelingspent air from a selected region of the building into said return ductwith part of said spent air traveling through the said heat dissipatingcourse and part of said spent air bypassing said heat dissipatingcourse.
 2. A ventilating system as described in claim 1, wherein saidproportioning means includes a vent formed in said return duct, covermeans for selectively closing said vent, and temperature responsivemeans for controlling said cover means.
 3. A ventilating system asdescribed in claim 2 further including means for supplying fresh air tosaid supply duct at a temperature below the desired room temperature. 4.A ventilating system as described in claim 3, further including meansfor collecting spent air in an elevated portion of said spaces at anelevated temperature.
 5. A ventilating system as described in claim 4,further including a central conditioning station connected to said airsupply duct and said air return duct for filtering and conditioning saidfresh air.
 6. Ventilation apparatus for a building having a compartmentcomprising, an air-to-air heat exchanger having a pair of heatexchanging courses extending therethrough, a fresh air supply duct andmeans connecting said supply duct to one end of one of said courses, anair diffuser connected to the opposite end of said one course fordirecting air from said one course into said compartment, an air returnduct through which spent air is exhausted from the compartment and meansconnecting said air return duct to one end of the other of said pair ofcourses, first passage means accommodating air flow from saidcompartment into the opposite end of said other course thus to introduceair into said air return duct, second passage means accommodating airflow from said compartment into said air return duct with such bypassingthe said other course of the exchanger thus to introduce air into saidreturn duct, and adjustable means operable on adjustment thereof tochange in the air introduced into said air return duct the proportion ofsuch air which is introduced by said first passage means and theproportion of such air which is introduced by said second passage means.7. The apparatus of claim 6 wherein said compartment is bounded by aceiling and a utility space in the building is provided above saidceiling, the exchanger is located above said ceiling in said utilityspace, and said first and second passage means communicate with saidcompartment through said ceiling.
 8. The apparatus of claim 6, whereinsaid adjustable means is thermostatically controlled.
 9. Ventilatingapparatus for a building with means for regulating the temperature ofair in selected regions of the building comprising, an air-to-air heatexchanger for each of said selected regions, each exchanger having aheat receiving course and a heat dissipating course, a fresh air supplyduct and a connection between the fresh air supply duct and one end ofthe heat receiving course of each exchanger, an air diffuser connectedto the opposite end of the heat receiving course of each exchanger fordirecting air from the receiving course into a selected region of thebuilding, an air return duct, and proportioning means for each exchangerfor channeling spent air from a selected region of the building intosaid air return duct with part of said air traveling through said heatdissipating course of the exchanger and part of said spent air bypassingsaid heat dissipating course.